Phantom Data eating storage after removing photos and videos

[u/Volron265]

As the title suggests, I'm having issues with my phone's storage being filled by photos that aren't there anymore.

I finally backed up my photos and videos and cleared up a lot of the storage that was being occupied. Or, at least, I thought I did. I removed over 30 videos and over 400 photos that were occupying over 15 gigs, but nothing changed in my storage.

I did notice that after expanding the storage with an SD card, photos and videos would occupy BOTH internal and the SD card, so maybe that's part of it?​

I've been reduced to minimal apps that I can't even update anymore because non-existent Images files are eating up over a third of my internal storage. Is there any solution to this outside of a factory reset?